Waits for a text to appear (by default waits for 1sec).
Element can be located by CSS or XPath.
Narrow down search results by providing context.

```js
I.waitForText('Thank you, form has been submitted');
I.waitForText('Thank you, form has been submitted', 5, '#modal');
```

@param {string }text to wait for.
@param {number} [sec=1] (optional, `1` by default) time in seconds to wait
@param {CodeceptJS.LocatorOrString} [context] (optional) element located by CSS|XPath|strict locator.
@returns {void} automatically synchronized promise through #recorder
